Large mode field photonic crystal fiber (PCF) with high damage threshold and nonlinear threshold and good heat dissipation capability has always been the focus of research at home and abroad. Shanghai Institute of Optics and Fine Mechanics, Academia Sinica, for the first time in the world put forward the concept of all-solid-state optical fiber doped with rare earth ions. This solution replaces the air holes with low refractive index glass and avoids the defects caused by the existence of air holes, making it possible to use an all-fiber laser. At the same time, the use of soft glass significantly improves the pump absorption and nonlinearity Threshold.
Using a 6wt% ytterbium-doped high-quality phosphate glass, Shanghai Komatsu Co., Ltd. successfully fabricated a single-mode output with a core diameter of 17 micrometers by a combination of tube-sticking and stacking methods. The polarization-maintaining phosphoric acid Salt all solid-state photonic crystal fiber, 13.8W laser output is achieved in ~ 40cm optical fiber, and the polarization maintaining performance of this kind of optical fiber is achieved by changing the optical fiber symmetry. The results are published in Scientific Reports [ScientificReports, 5, 8490, 2015].
Due to the stable properties of quartz optical fiber, low transmission loss and high softening point, the current research on large mode field optical fiber mainly focuses on quartz optical fiber. However, the low solubility and low threshold of nonlinearity of quartz optical fiber make the pump absorption rate low, meanwhile the nonlinear effect is obvious at high power output, which seriously affects the further output of fiber laser.
At present, most of the low refractive index rods constituting the photonic crystal arrangement in the quartz PCF are made of air, which not only makes the preparation and storage of the optical fiber complicated and costly but also lowers the thermal conductivity of the air, When the phenomenon of unstable mode, affecting the stability of the beam quality. At the same time, the existence of air holes makes it difficult to weld with the traditional pigtail output device, including the pump source, resulting in an all-fiber laser. The all-solid-state photonic crystal fiber developed by Shanghai Institute of Optics and Fine Mechanics proposed a new large-mode field optical fiber structure, which successfully solved the shortcomings of difficult and difficult-to-implement all-fiber laser such as difficult welding, poor heat dissipation and hard fiber.
Longitudinal Finned Tube,Longitudinally Finned Tube,Copper Finned Tube,Boiler Finned Tube
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